In this computer-animated sequel to ICE AGE, prehistoric creatures face a new problem: their icy world is melting. Manny (voiced by Ray Romano), seemingly the last woolly mammoth on Earth, and his pals--a saber-toothed tiger named Diego (Denis Leary) and a sloth named Sid (John Leguizamo)--are perfectly content in their ice-covered valley. When con artist Fast Tony (Jay Leno) claims that their home will soon be underwater and the world is about to end, they think he's kidding. But to everyone's surprise, the shady fast talker is right. Manny, Diego, and Sid soon discover that the valley will flood in days. Following the advice of a vulture (Will Arnett) who is hoping for the worst, a bevy of animals begin to make their way to the end of the valley in search of a boat that will save them from the flood.

En route, sad sack Manny is startled when he encounters another woolly mammoth, Ellie (Queen Latifah). As happy as Manny is to see another one of his kind, there's a problem: Ellie is convinced that she's a possum like her hyperactive brothers, Crash (Seann William Scott) and Eddie (Josh Peck). And to make matters worse, the melting of the ice has released some ferocious sea creatures that had literally been frozen in time. Will Ellie finally realize that she's a gigantic woolly mammoth and not a pint-sized possum? Is it really the end of the world? Can Manny and the rest of the animals in the valley survive the impending flood? And will Manny be able to leave the past behind now that he knows he's not alone? Saber-tooth squirrel Scrat and his quest for an acorn once again provide additional comic relief throughout the film.